The perimeter of a rectangle is 108cm. The ration of its length to its width is 7:2 what is the area of the rectangle in cm2?

Question

The perimeter of a rectangle is 108cm. The ration of its length to its width is 7:2 what is the area of the rectangle in cm2?

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Ngọc Diệp 6 hours 2021-07-22T11:36:14+00:00 1 Answers 0 views 0

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    2021-07-22T11:38:07+00:00

    Answer:

    504 cm²

    Step-by-step explanation:

    Let the length and the width of the rectangle be L cm and W cm respectively.

    Perimeter= 2(L +W)

    2(L +W)= 108

    L +W= 108 ÷2

    L +W= 54

    L= 54 -W —–(1)

     \frac{L}{W}  =  \frac{7}{2}

    Cross multiply:

    2L= 7W —–(2)

    Substitute (1) into (2):

    2(54 -W)= 7W

    Expand:

    108 -2W= 7W

    +2W on both sides:

    9W= 108

    Divide both sides by 9:

    W= 108 ÷9

    W= 12

    Substitute W= 12 into (1):

    L= 54 -12

    L= 42

    Area of rectangle

    = length ×width

    = LW

    = 42(12)

    = 504 cm²

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Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )